Magosi, the Waterveil, Kelpie Guide, and Rings of Brighthearth

Prerequisites

• Magosi, the Waterveil on the battlefield
• Kelpie Guide on the battlefield
• Rings of Brighthearth on the battlefield
• each turn available

Steps

1. Activate Magosi's second activated ability by paying and tapping it
2. Rings of Brighthearth triggers
3. Choose not to pay
4. Resolve the Magosi ability, putting an eon counter on it and skipping your next turn
5. Activate Kelpie Guide by tapping it, targeting Magosi
6. Rings of Brighthearth triggers
7. Choose not to pay
8. Resolve the Kelpie Guide ability, untapping Magosi
9. Activate Magosi's third activated ability by tapping it, removing an eon counter from it, and returning it to your hand
10. Rings of Brighthearth triggers, causing you to pay to copy Magosi's ability
11. Resolve both instances of Magosi's ability, causing you to take two extra turns after this one
12. Play Magosi
13. Move to your second extra turn
14. The first extra turn will be skipped due to the ability activated in step 1
15. Repeat

Results

• Infinite turns
• Lock